The Diesel Stop banner
1 - 20 of 21 Posts

·
Registered
Joined
·
498 Posts
Discussion Starter · #1 ·
Recently pulled a load of about 11K from IN to AZ. After I got around NM, if my EGT was above 900deg my coolant gauge showed it was climbing.
It didn't seem to matter if the tuner was used or not, anytime EGT got high the coolant temp would climb. I spent almost all day without the A/C and running the hills slow so I wouldn't overheat.
I had this once before, but since have changed the fan clutch, serpentine and idler pulley assy. It doesn't seem to be a problem unless the air is thin.

I do remember reading before that the CAC and radiator should be removed and the fins cleaned out real good as to accumulated dirt, bugs etc. I have had a bug guard on for a long time, but I might have a lot of dirt. I took off the bug guard thinking it was restricting air flow.

Why is this truck overheating? Thanks.
 

·
Registered
Joined
·
10,544 Posts
The factory gage is..well a idiot gage so without knowing a true temp it may not be as hot as you may think. Did your fan clutch hook up.you can tell by the drag on the engine and the noise. Unless it did and your really running hot......I would suspect that the lower Rad hose may be collapsing or your Rad is partially plugged. Only other thing is the Thermostat is sticking or a long shot the map sensor???

Cary
 

·
Registered
Joined
·
6,944 Posts
How high were the EGT's? 900 is nothing!!! If your fan clutch engaged you would know, it sounds like a Jet airplane taking off under the hood. It scared me to death the first time it came on. How warm did the temp gauge show?
NCH
 

·
Registered
Joined
·
498 Posts
Discussion Starter · #4 ·
Thanks Cary and Hornet. Hadn't thought about the hose collapsing. It is pretty old and should be replaced.
The funny thing was that I never really heard the fan engage. Same before when I had the problem, didn't hear the fan. (That is why I changed the fan clutch last time)
So...I may not really have a problem? I suppose an aftermarket temp gauge would be a good idea. I could put a probe into my coolant filter housing.
And cleaning out the fins will happen.

On the EGT, yeah I know 900 is nothing. I usually run the hills under load to 1250. When I would back off and run 900, the factory temp gauge would stay in the normal range.

Thanks for the ideas and replies.
 

·
Registered
Joined
·
858 Posts
If you aren't hearing the fan clutch engage, then there's where you need to start. Like NCHornet said, it's LOUD!
 

·
Registered
Joined
·
498 Posts
Discussion Starter · #6 ·
If you aren't hearing the fan clutch engage, then there's where you need to start. Like NCHornet said, it's LOUD!
Well...I do hear it come on sometimes, just not when the temp gauge shows hot. And it was replaced with a new one...so I am fairly sure it is working.
Thx.
 

·
Registered
Joined
·
9,922 Posts
Well...I do hear it come on sometimes, just not when the temp gauge shows hot. And it was replaced with a new one...so I am fairly sure it is working.
Thx.
The fan clutch is activated by the air temperature coming through the stack of CAC, radiator, AC condensor etc., NOT the coolant temperature.
 

·
Registered
Joined
·
6,944 Posts
The fan should come on before you see the temp gauge rise. If you were toting a good load up a decent grade in Summer temps ( the conditions you describe) you should have heard it come on. I beg to differ I think the problem may be the fan clutch. Was it new/rebuilt, junkyard????

NCH
 

·
Registered
Joined
·
498 Posts
Discussion Starter · #9 ·
The fan should come on before you see the temp gauge rise. If you were toting a good load up a decent grade in Summer temps ( the conditions you describe) you should have heard it come on. I beg to differ I think the problem may be the fan clutch. Was it new/rebuilt, junkyard????

NCH
I hear you, and the first time it happened months ago was climbing out of Denver with a good load in 100deg temps, but I never heard the fan clutch engage. I replaced it with a new Ford Motorcraft.

Will replace the lower hose...clean out the cooling fins and install a temp gauge so I will have more data IF it happens again.
 

·
Registered
Joined
·
498 Posts
Discussion Starter · #10 ·
Thermostat failure

I found that my 203deg thermostat had failed yesterday. I replaced it with OEM. Doesn't explain totally why the fan clutch wasn't seeing high temp and turning on though.:shrug03:
I did install a coolant temp gauge in an unused port of my coolant filter housing. I am only seeing about 150deg though at normal engine temp.
Do you think that's real? Being that the coolant filter port is bypassing the thermostat, it could be real I suppose.
We'll see how it goes from here.
 

·
Registered
Joined
·
627 Posts
The temp you are seeing is probably lower than what is actual. However, once you find what is normal, the numbers are not that important. It is the change that is. My temp sensor is also in the filter head. With the 203 T-stat, I see 180º as the norm. I believe that is lower than actual, but I can monitor and see changes, which is the important thing.
jgr
 

·
Registered
Joined
·
21 Posts
Hello all! New to this site and also a new diesel owner. I recently moved from Omaha (1ooo ft elev.) to Albuquerque (6000 ft elev.) and have noticed a considerable drop in performance and increased engine temps on my 6.4 F-250. I asked the dealer about re-calibrating the computer and got the "void the warranty" speech... I usually let the truck run for about 5 min in my driveway to cool itself down in this heat. Now for my questions...
1) is there a high altitude setting the dealer can adjust?
2) I don't know about the cooling fan, but once I heard something like a belt squealing REALLY LOUD when I shut it down- was this the cooling fan?
Thanks!
 

·
Registered
Joined
·
498 Posts
Discussion Starter · #13 ·
Hello all! New to this site and also a new diesel owner. I recently moved from Omaha (1ooo ft elev.) to Albuquerque (6000 ft elev.) and have noticed a considerable drop in performance and increased engine temps on my 6.4 F-250. I asked the dealer about re-calibrating the computer and got the "void the warranty" speech... I usually let the truck run for about 5 min in my driveway to cool itself down in this heat. Now for my questions...
1) is there a high altitude setting the dealer can adjust?
2) I don't know about the cooling fan, but once I heard something like a belt squealing REALLY LOUD when I shut it down- was this the cooling fan?
Thanks!
Welcome. The thin air will change things about your truck that you were used to. I don't think there is a re-calibration that can be done as the sensors see barometric pressure on startup (at least on the 7.3)
Try posting in the 6.4 forums for a possible better response.
And welcome to high altitude.
 

·
Registered
Joined
·
342 Posts
My 02 is doing the same thing -- pulling a bit of weight (10K) -- anything above 10,000' -- I have to keep the EGTs below 900 or she starts to cook -- fan clutch is working --- radiator has been cleaned -- new belt ----------UGH!
 

·
Registered
Joined
·
498 Posts
Discussion Starter · #15 ·
My 02 is doing the same thing -- pulling a bit of weight (10K) -- anything above 10,000' -- I have to keep the EGTs below 900 or she starts to cook -- fan clutch is working --- radiator has been cleaned -- new belt ----------UGH!
I haven't had trouble since I replaced the thermostat. The newly installed water temp gauge works nicely and shows a good max of 200deg.
Haven't run in 10K ft though....wow....that's up there.
 

·
Registered
Joined
·
2 Posts
my 1999 Dodge 3500 dually 4X4 overheats everytime I pull my 5th wheel up a mountain pass... new Jasper Cummins diesel engine in it , new radiator (twice), new fan clutch, new cummins thermostat, new turbo, pretty much everything under the hood is new... still overheats on the mountain passes.... have to stop a couple of times going up any pass and let her cool down... and it's not the temp gauge... it is HOT... steaming and boiling... nobody knows why... Jasper says it needs to be tuned for high altitude... Dodge dealerships say there is no tuning for high altitudes...I'm at a loss... don't know what to do now... the new engine only has 9,000 miles on it...it only does it when I am pulling my 5th wheel... it weighs about 12,000 lbs... anybody? ... any clues?
 

·
Registered
Joined
·
2,846 Posts
If the rest is new check to make sure the coolant cap holds pressure.
I'm unfamiliar with dodges but I know A bad cap will not let the system hold pressure, which raises the boiling temp.
 

·
Registered
Joined
·
447 Posts
The only thing that you can do for high altitude is to back out of the throttle. You just don't have enough air to burn the fuel you are putting into the motor. Which creates high exhaust temp. Which puts too much heat into the heads and cooling system. And now you also have thin air coming thru the radiator so you have lost cooling capacity there also. Its just a fact of life with engines in very high altitudes pulling big loads running at close to their max horsepower for a certain amount of time. If you don't believe me go to 12,000 ft and see how far you can run before you get winded
 

·
Registered
Joined
·
15 Posts
This is an old thread, but for newer readers, I have to leave this comment. Nobody here has mentioned the obvious. I discovered it with a 1989 gas pickup with a Chevy 350, but same principles apply. I moved from 3k elevation to 8 k, Colorado Rockies. My pickup would inexplicably heat up even in freezing temps. No load, just driving. New water pump, good thermostat, I tested it in boiling water, new radiator, etc. etc. I had a 195 thermostat for the cold weather. FINALLY, figured it out. Thin air may be a factor, but that was not my problem. Water at that altitude boils at about 197 degrees, depending on altitude. I was actually driving daily between 8000 and 9300 ft elevation. At 9k, water boils at 195. My thermostat wasn’t even opening until the water was boiling away from the heads and combustion chamber, so I would get a big air pocket in there. And if my thermostat was a couple of degrees off? Yeah, when the thermostat finally opened, it SHOULD pump that out air of there, and usually did if I wasn’t under load. If I was under load, pulling a hill or something, the cooling system couldn’t catch up because the combustion chamber area was already way too hot and vaporizing any water that got on it, so I would end up by the side of the road with all of my water boiled out. Amazing I didn’t blow a head gasket or warp the heads.

As soon as I dropped a 180 degree thermostat in, my troubles were over. Not one more problem. Cooling system was plenty adequate, just needed to be in use before the water got vaporized.

My heater didn’t run as hot in the winter, and that was not pleasant, but hey, you do what you have to do. If I could have gotten a 185 or 188, I would have, but not available.

Most of you are running a stock 192 or 195 and some of you are even using a 203 high temp thermostat. You may get away a 192 and even a 195 if empty, but not under load at real high altitude.

My suggestion: if you want a higher temp thermostat and very seldom go to high altitude, carry a lower temp thermostat with you and put it in just before you climb the Rockies. On my 99 f350, I can change that sucker in about 5 minutes. If you catch the coolant and put it back in, no harm, no foul. However, MAKE SURE you get a long type thermostat, not a short one just because it fits and it is cheaper. That long tail controls the water flow into the block and with the wrong thermostat, you can still have heating and flow problems due to the thermostat. It’s all part of the engineering of the engine.
 
1 - 20 of 21 Posts
Top